." >>> to south africa now, where more than 50 world leaders will arrive to honor nelson mandela. that number growing. president obama leaving on air force one tomorrow night with the first lady, of course, who met mandela with her daughters. the obamas have invited former president george w. bush and laura bush to travel them. the bushes have said they will. former president clinton and hillary clinton making the trip, as will former president jimmy carter, too. tonight, we learned queen elizabeth, who met mandela a number of times, has asked that her son prince charles attend in her place. and on this sunday in south africa, a day of prayer. and word from one of nelson mandela's daughters, during his final days. abc's byron pitts is there. >> reporter: this sunday was soaked in symbolism. the former township, once the epicenter of the anti-apartheid movement. grief and gratitude stretched across generations. he spoke for a nation. >> i'm here today, he fought for our freedom. if it wasn't for him, we wouldn't be here. we wouldn't be having all the things that we have. >> reporte